Lets talk about something other than CMI or BMI:eek:
The Pic’s are of a 2 1/2 ton Bryant heat pump up-flow; blower above the A-coil. The local return air filter below the unit had the filter matted over and was dislodged from its filter grill. I decided to have a look at the A-coil fins as it had a easy excess panel and sure enough the coil was matted over as indicated in the Pic. I make my determination about the coil depending on basically how much lint is on the blower motor and blower wheel.
I also check the heat strips with a amp meter as indicated. This furnace had three strips; each one was drawing 21 amps. These strips were visible once the blower motor cover was removed.
Yes for you hard heads I still consider this a visual inspection. How else can you determine if an electrical furnace is performing as intended with all strips in working order:D